摘要
为研究B+F双相X80管线钢各向异性对安全服役的影响,采用金相扫描电镜观察、慢应变拉伸法和电化学极化法,在模拟海水环境中,与轧制方向呈0°,45°,90°3种不同角度试样的B+F双相X80管线钢的慢应变拉伸和极化行为进行了分析。结果表明:双相X80管线钢组织由多边形铁素体和板条状贝氏体组成,铁素体和贝氏体含量近似为1∶1;在模拟海水环境慢拉伸条件下,B+F双相X80管线钢与轧制方向呈不同角度试样的屈服强度随取样角度的增大明显降低,说明海水对B+F双相X80管线钢具有明显的应力腐蚀作用;与轧制方向呈0°试样的X80管线钢的慢应变拉伸应力与应变曲线呈圆顶状,屈服强度和抗拉强度均最高,屈强比为0.81,均匀伸长率为13.4%,可以满足使用要求;与轧制方向呈90°试样的双相X80管线钢的自腐蚀电位最负,自腐蚀电流最大,耐海水腐蚀性能最差;与轧制方向呈45°试样的双相X80管线钢的自腐蚀电位最正,耐蚀性最优。研究B+F双相X80管线钢在模拟海水中的慢应变拉伸各向异性,可提高其安全服役性,对大变形管线钢的实际生产具有一定的借鉴价值。
In order to study the effect of anisotropy on the safe service of B+F dual-phase X80 pipeline steel,the slow strain tensile and polarization behaviors of hot rolled ferrite+bainite dual-phase X80 pipeline steel at three angles(0°,45°and 90°)with rolling direction were analyzed by metallography,scanning electron microscopy,slow strain tensile test and electrochemical polarization method in simulated seawater.The result shows that the dual-phase X80 pipeline steel is composed of polygonal ferrite and lath bainite,and the content ratio of ferrite and bainite is about 1∶1.The slow tension yield strength of X80 pipeline steel with different angles from rolling direction decreases significantly with the increase of sampling angle in simulated seawater environment,which indicates that seawater has obvious stress corrosion to X80 pipeline steel;the slow strain tensile stress-strain curve of B+F dual-phase X80 pipeline steel parallel to rolling direction(0°)shows dome shape,the yield strength and tensile strength are the highest,the yield strength ratio is 0.81,and the uniform elongation is 13.4%,which can meet the application requirement;the self-corrosion potential of B+F dual-phase X80 pipeline steel perpendicular to the rolling direction(90°)is the most negative and the self-corrosion current is the largest,which indicates the seawater corrosion resistance is the worst;the corrosion resistance of dual-phase pipeline steel in the direction of 45°from the rolling direction in simulated seawater is the best due to the most positive self-corrosion potential.The research on the slow strain tensile anisotropy of B+F dual-phase X80 pipeline steel in simulated seawater environment can improve its safe service,and has some reference value for the actual production of large deformation pipeline steel.
作者
马静
王申豪
张双杰
范利锋
MA Jing;WANG Shenhao;ZHANG Shuangjie;FAN Lifeng(School of Material Science and Engineering,Hebei University of Science and Technology,Shijiazhuang,Hebei 050018,China;Hebei Key Laboratory of Material Near-Net Forming Technology,Shijiazhuang,Hebei 050018,China;Hebei Innovation Center for Superalloy Investment Casting Technology,Huanghua,Hebei 061100,China;Steel Ball Technology Innovation Center of Hebei Province,Handan,Hebei 056000,China;Transportation Institute of Inner Mongolia University,Hohhot,Inner Mongolia 010021,China)
出处
《河北科技大学学报》
CAS
2020年第5期455-461,共7页
Journal of Hebei University of Science and Technology
基金
国家自然科学基金(51761030,51701064)
内蒙古自然科学基金(2019MS05081)。
关键词
金属材料工程
双相管线钢
各向异性
慢应变拉伸
极化行为
海水腐蚀
metal materials and engineering
dual-phase pipeline steel
anisotropy
slow strain tensile
polarization behavior
seawater corrosion
